Nitrogen purge hopper

Abstract

A hopper apparatus ( 100 ) provides a conveyance passage ( 150 ) equipped with a nitrogen purge system. In operation, the hopper apparatus ( 100 ) is installed over an opening of a process vessel ( 200 ). Chemical matter may be conveyed through the conveyance passage ( 150 ) to land within the process vessel ( 200 ). The hopper apparatus may have a flap valve ( 141 ) that serves to isolate the interior space of a process vessel ( 200 ) from the ambient environment outside the process vessel ( 200 ). The hopper apparatus ( 100 ) may also inject nitrogen at various rates into the falling stream of chemical matter as it is conveyed into a process vessel ( 200 ). The hopper apparatus ( 100 ) may also provide a ventilation sleeve ( 180 ) providing ventilation and extraction of dust and vapors emitted from the falling stream of chemical matter.

What is claimed is: 
     
       1. A hopper apparatus  100 , comprising:
 a receptacle member  110 , a purge member  120 , and an adapter  130  mutually engaged in a column; 
 a conveyance passage  150  running through the receptacle member  110 , the purge member  120 , and the adapter  130 ; 
 a tunnel  121  of the purge member  120  circumscribing the conveyance passage  150 , wherein the tunnel  121  has a lower mouth  122  enclosed by the adapter  130 ; 
 a pivotable flap valve  141  at the lower mouth  122 ; 
 an annular ring  142  encircling the lower mouth  122  of the tunnel  121 , the annular ring  142  being perforated with a plurality of inward-facing injection jets  153  about the circumference of the annular ring  142 ; 
 gas feed ports  143  connected to the injection jets  153 , the gas feed ports  143  including an injection port connected to a nitrogen control valve; and 
 a valve lever  154  connected to the flap valve  141  and to the nitrogen control valve; 
 wherein the top of the conveyance passage  150  opens at a mouth  111  of the receptacle member  110  and the bottom of the conveyance passage  150  opens at a lower opening  132  of the adapter  130 ; 
 wherein the flap valve  141  is pivotable between a closed position and an opened position, wherein the flap valve  141  in the closed position obstructs the lower mouth  122  of the purge member  120 ; 
 wherein the nitrogen control valve has a closed position and an opened position, wherein the nitrogen control valve in the closed position obstructs the connection between the injection jets  153  and the injection port; and 
 wherein the valve lever  154  is operable to place the flap valve  141  in the opened position of the flap valve  141 , and to place the nitrogen control valve in the opened position of the nitrogen control valve. 
 
     
     
       2. The hopper apparatus  100  of  claim 1 , wherein while the flap valve  141  is in the opened position of the flap valve  141 , a non-powered retract mechanism biases the flap valve  141  towards the closed position of the flap valve  141 . 
     
     
       3. The hopper apparatus  100  of  claim 1 , wherein the lower mouth  122 , the flap valve  141 , and the annular ring  142  are inclined downward on a side of the hopper apparatus. 
     
     
       4. The hopper apparatus  100  of  claim 1 , wherein the flap valve  141  is attached to a lever arm  156  having a notch  157 ;
 wherein the flap valve  141  pivots by rotation of the lever arm  156 ; 
 wherein the annular ring  142  fits within the notch  157  while the flap valve  141  is in a closed position of the flap valve  141 . 
 
     
     
       5. The hopper apparatus  100  of  claim 1 , further comprising a nitrogen supply connected to the gas feed ports  143 ;
 wherein while the nitrogen control valve is in the closed position of the nitrogen control valve, nitrogen flows from the nitrogen supply to the injection jets  153  at a first volumetric flow rate; 
 wherein while the nitrogen control valve is in the open position of the nitrogen control valve, nitrogen flows from the nitrogen supply to the injection jets  153  at a second volumetric flow rate greater than the first volumetric flow rate. 
 
     
     
       6. The hopper apparatus  100  of  claim 1 , wherein the purge member  120  and the adapter  130  form a purge chamber  136 ;
 wherein while the flap valve  141  is in the closed position of the flap valve  141 , nitrogen injected through the injection jets  153  into the purge chamber  136  is prevented from rising through the tunnel  121  by the flap valve  141 ; 
 wherein while the flap valve  141  is in the open position of the flap valve  141 , nitrogen injected through the injection jets  153  into the purge chamber  136  is prevented from rising through the tunnel  121  by an eduction effect generated by the flow of nitrogen at a second volumetric flow rate. 
 
     
     
       7. The hopper apparatus  100  of  claim 1 , further comprising a ventilation sleeve  180  mounted to the mouth  111 , wherein the ventilation sleeve  180  encircles at least a portion of the perimeter of the mouth  111 ;
 wherein the ventilation sleeve  180  is perforated with a plurality of ventilation slots  183  about the circumference of the ventilation sleeve  180 ; 
 wherein the ventilation slots  183  are connected to an exhaust port  184 . 
 
     
     
       8. The hopper apparatus  100  of  claim 1 , wherein the receptacle member  110 , the purge member  120 , and the adapter  130  are secured together in a column by attaching a clamp  139  anchored to the adapter  130  to the receptacle member  110 .